An approach to the toxicity and toxicokinetics of aflatoxin B1 and ochratoxin A after simultaneous oral administration to fasted F344 rats

Humans are exposed to the hepatotoxic aflatoxin B1 (AFB1) and nephrotoxic ochratoxin A (OTA) through diet. However, kinetic and toxicological data after their co-administration are scarce. In this study, a single oral dose of AFB1 (0.25mg/kg bw)+OTA (0.5mg/kgbw) was administered to fasted F344 rats. Blood, liver and kidney were harvested at different timepoints for mycotoxins quantification, relative weight calculation, clinical biochemistry and histopathology analysis. Toxicity parameters pointed to acute toxicity in liver due to AFB1. No remarkable toxicity was observed in kidneys or immunological organs. Maximum observed concentrations in plasma (C(max)) were at 10min and 2h for AFB1 and OTA, respectively. AFB1 plasma concentration could indicate a rapid absorption/ metabolism of the mycotoxin; and AFB1 liver and kidney concentrations were lower than LOQ and LOD, respectively. For OTA, C(max) was 4326.2μg/L in plasma. In kidney and liver C(max) was reached at 8h and concentrations were very similar between both organs at all timepoints. Due to the low levels of AFB1, the effect of OTA on AFB1 kinetics could not be assessed. However, AFB1 seems not to affect OTA kinetics, as its profile seems very similar to kinetic studies performed only with OTA in similar conditions

Design and calibration process of solar sensors for small satellite missions

In combination with magnetometers, solar sensors are one of the most used instruments for determining the attitude of small satellites. These devices use the photoelectric effect to produce an electrical current. This electrical current, or the voltage associated with the electrical circuit of the solar sensor, is measured in order to compute the angle of incident of the sun with the normal direction of the sensor. Then, together with the computed angles of other solar sensors on different faces of the satellite, the sun's direction in relation to a spacecraft can be calculated. Solar sensors are simple devices whose low-cost design based on photodiodes can be developed by students. During the design and fabrication process of a solar sensor, one of the most important tasks is the accurate estimation of the sensor response in the space radiative environment. It is possible to simulate the Sun’s radiation spectrum, but the equipment and facilities needed are costly for a university project. In this paper, the design and calibration process of satellite solar sensors carried out together by students and teachers from the Master's degree in Space Systems (MUSE) from the Universidad Politécnica de Madrid is described. The process uses a calibration method that calibrates the photodiodes for space use without simulating the Sun’s radiation spectrum in the laborator

Zaintza informala Euskal Autonomia Erkidegoan: Zaintzaileen premiak

Lan honetan EAEko nagusien zaintza lana bere gain hartzen duten pertsonen azterketa sakon bat egiten da. Ikerlana ‘elurrezko bola’ deritzon metodologiaz osatutako lagin batean oinarritzen da eta, egindako inkestaren datuez baliatuz, zaintzaile hauen ezaugarri eta beharrak emeten ditu aditzera, zaintzaren edukia eta erakundeei egotzitako bete beherrakin batera. Azterketa sakona egin ostean, egileek hainbat gomendio estrategiko egiten dituzte etorkizunari begira

Validation of a UHPLC-FLD method for the simultaneous quantification of aflatoxins, ochratoxin A and zearalenone in barley

A fast and simple UHPLC-FLD method has been developed for the simultaneous determination in barley of aflatoxins (B1, G1, B2 and G2), ochratoxin A (OTA) and zearalenone (ZEA), some of the most important mycotoxins due to their toxicity and occurrence. The procedure is based on the extraction of the six mycotoxins with a mixture of acetonitrile and water, and the purification of the extract with immunoaffinity columns before analysis. Detection of AFB1 and AFG1 is improved using a photochemical reaction. The method has been validated with satisfactory results. Limits of detection were 340 ng kg-1 for ZEA, 13 ng kg-1 for OTA and varied from 0.5 to 15 ng kg-1 for aflatoxins. Recovery percentages were between 78.2 and 109.2%. After being validated, the method has been successfully applied to 20 barley samples cultivated in a region of northern Spain (Navarra)

Molecular Characterization of Cryptosporidium spp. in Cultivated and Wild Marine Fishes from Western Mediterranean with the First Detection of Zoonotic Cryptosporidium ubiquitum

Altres ajuts: Ministerio para la transición ecológica y el reto demográfico 2019/1476 i 2020/792Cryptosporidium is a widespread pathogen that infects a broad range of vertebrates, including humans, in which it is one of the main causes of diarrhea worldwide. Marine fishes also harbor Cryptosporidium species, including zoonotic ones. The goal of this study is to evaluate the presence of Cryptosporidium species in edible marine fishes using molecular tools. The area of study, located in the Western Mediterranean, is an important area for marine fish production and capture. The following three groups were studied: cultivated fish, wild fish that aggregate in the surroundings of marine fish farms and wild fish from extractive fisheries. Results show that the most affected group is the group of wild fish from the vicinity of fish farms. Two species were mainly identified, C. molnari (fish specific) and zoonotic C. ubiquitum. The presence of zoonotic C. ubiquitum in two European sea bass (Dicentrarchus labrax) highlights a potential risk for fish consumers. Fish not only harbor host-specific species/genotypes of Cryptosporidium, but also species like zoonotic C. parvum or anthroponotic C. hominis, which can pose a risk for fish consumers. This study aims to investigate fish cryptosporidiosis in an important aquaculture and fishery area of the Western Mediterranean (Comunidad Valenciana, Spain). We analyzed 404 specimens belonging to the following three groups: cultivated fish (N = 147), wild synanthropic fish (N = 147) and wild fish from extractive fisheries (N = 110). Nested PCR targeting the 18S rRNA gene, followed by sequencing and phylogenetic analysis, were performed. Positive isolates were also amplified at the actin gene locus. An overall prevalence of 4.2% was detected, with the highest prevalence in the synanthropic group (6.1%). C. molnari was identified in thirteen specimens from seven different host species. Zoonotic C. ubiquitum was detected in two European sea bass (Dicentrarchus labrax). One isolate similar to C. scophthalmi was detected in a cultivated meagre (Argyrosomus regius), and one isolate, highly divergent from all the Cryptosporidium species/genotypes described, was identified from a synanthropic round sardinella (Sardinella aurita). This study contributes to increasing the molecular data on fish cryptosporidiosis, expanding the range of known hosts for C. molnari and identifying, for the first time, zoonotic C. ubiquitum in edible marine fishes, pointing out a potential health risk

Validation of a UHPLC-FLD analytical method for the simultaneous quantification of aflatoxin B1 and ochratoxin a in rat plasma, liver and kidney

A rapid and simple method for the simultaneous quantification of AFB1 and OTA in rat plasma, liver and kidney by UHPLC-FLD has been successfully validated according to the following criteria: selectivity, stability, linearity, precision, accuracy, recovery, robustness and limits of quantification and detection. The extraction method, calibration curves and chromatographic conditions are common for the three matrices. Plasma and homogenized tissue samples (100 μL) were extracted with acetonitrile-formic acid mixture (99:1) (300 μL). Chromatographic separation was performed with a mixture of water and acetonitrile:methanol (50:50), both acidified with 0.5% of formic acid using a gradient profile. The method avoids the use of immunoaffinity columns and allows reduction of sample and solvent volumes as well as toxic wastes. The detection is based on a photochemical reaction which enhances the AFB1 response without affecting the OTA signal before reaching the fluorescent detector. The mycotoxin recovery for each matrix was very efficient, between 93% and 96% for AFB1 and between 94% and 96% for OTA. For both mycotoxins the LOQs were 2 μg/L in plasma and 8 μg/kg in liver and kidney. The method has successfully been applied to rat samples after a single oral administration of a mixture of AFB1 and OTA and it could be a useful tool in toxicokinetic and toxicological studies

The upper-airway microbiome as a biomarker of asthma exacerbations despite inhaled corticosteroid treatment.

BACKGROUND: The response to inhaled corticosteroids (ICS) in asthma is affected by the interplay of several factors. Among these, the role of the upper-airway microbiome has been scarcely investigated. We aimed to evaluate the association between the salivary, pharyngeal, and nasal microbiome with asthma exacerbations despite receipt of ICS. METHODS: Samples from 250 asthma patients from the Genomics and Metagenomics of Asthma Severity (GEMAS) study treated with ICS were analyzed. Control/case subjects were defined by the absence/presence of asthma exacerbations in the past 6 months despite being treated with ICS. The bacterial microbiota was profiled by sequencing the V3-V4 region of the 16S rRNA gene. Differences between groups were assessed by PERMANOVA and regression models adjusted for potential confounders. Afalse discovery rate (FDR) of 5% was used to correct for multiple comparisons. Classification models of asthma exacerbations despite ICS treatment were built with machine learning approaches based on clinical, genetic, and microbiome data. RESULTS: In nasal and saliva samples, case subjects had lower bacterial diversity (Richness, Shannon, and Faith indices) than control subjects (.007≤ P≤ .037). Asthma exacerbations accounted for 8% to 9% of the interindividual variation of the salivary and nasal microbiomes (.003≤ P≤ .046). Three, 4, and 11 bacterial genera from the salivary, pharyngeal, and nasal microbiomes were differentially abundant between groups (4.09*10-12≤ FDR≤ 0.047). Integrating clinical, genetic, and microbiome data showed good discrimination for the development of asthma exacerbations despite receipt of ICS (AUCtraining: 0.82 and AUCvalidation: 0.77). CONCLUSION: The diversity and composition of the upper-airway microbiome are associated with asthma exacerbations despite ICS treatment. The salivary microbiome has a potential application as a biomarker of asthma exacerbations despite receipt of ICS

Effects of fasting and gender on ochratoxin A toxicokinetics in F344 rats

Ochratoxin A (OTA) is a mycotoxin that causes renal tumors in rats, particularly in males. In previous kinetic studies performed in fed conditions (Vettorazzi et al., 2008), mature F344 male rats presented a significantly lower OTA bioavailability than females and young animals. The objective of the present study was to evaluate two factors which could explain this different kinetic profile: the presence of food and the male-specific protein alpha-2u-globulin. Therefore, a 24h kinetic study has been performed in rats under fasting conditions. Food ingestion has been controlled in both sexes during two months. The presence of alpha-2u-globulin in the urine has been analyzed with SDS-gradient mini-gel electrophoresis. Fasting tends to increase the maximum OTA plasma concentrations and the rate of absorption. The relative bioavailability is significantly increased under fasting conditions only in males. Mature males consumed a higher amount of food but, as the OTA dose administered, it was proportional to body weight. The reason why the OTA bioavailability is more affected in presence of food only in males is unclear. Several possibilities, such as differences in gastric emptying, OTA-food interactions and the involvement of alpha-2u-globulin are discussed

Genotoxicity of aflatoxin B1 and ochratoxin A after simultaneous application of the in vivo micronucleus and comet assay

Aflatoxin B1 (AFB1) and Ochratoxin A (OTA) are genotoxic mycotoxins that can contaminate a variety of foodstuffs, the liver and the kidney being their target organ, respectively. The micronucleus (MN) assay (bone marrow) and the comet assay (liver and kidney) were performed simultaneously in F344 rats, treated with AFB1 (0.25 mg/kg b.w.), OTA (0.5 mg/kg b.w.) or both mycotoxins. After AFB1 treatment, histopathology and biochemistry analysis showed liver necrosis, focal inflammation and an increase in Alanine Aminotransferase and Aspartate Aminotransferase. OTA alone did not cause any alteration. The acute hepatotoxic effects caused by AFB1 were less pronounced in animals treated with both mycotoxins. With regard to the MN assay, after 24h, positive results were obtained for AFB1 and negative results were obtained for OTA, although both toxins caused bone marrow toxicity. In the combined treatment, OTA reduced the toxicity and the number of MN produced by AFB1. In the comet assay, after 3h, positive results were obtained for AFB1 in the liver and for OTA in the kidney. The combined treatment reduced DNA damage in the liver and had no influence in the kidney. Altogether, these results may be indicative of an antagonistic relationship regarding the genotoxicity of both mycotoxins